Shoutbox

svchost is the Windows Service Host - it's used to "host" any running services you may be using. I wouldn't recommend ending it directly, use services.msc to disable unneeded services.

(You can also use Sysinternals [now owned by Microsoft] Process Explorer to see which services are running under which process).

Most of those are launcehd at startup and are pretty useless, such as jusched.exe which is the Java Update Scheduler, acrotray which must be used for Adobe Acrobat, etc.

You'll need to use msconfig or similar to temporarily disable certain startup tasks and see what breaks. It's unlikely to get you into a situation where the PC won't boot doing this - you can't disable necessary MS stuff from it. [Unless you play with boot.ini, don't do that]